van Dyck C H, Seibyl J P, Malison R T, Laruelle M, Wallace E, Zoghbi S S, Zea-Ponce Y, Baldwin R M, Charney D S, Hoffer P B
Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06510, USA.
J Nucl Med. 1995 Jul;36(7):1175-81.
The effect of age on human striatal dopamine (DA) transporters was investigated with SPECT using the ligand [123I]2 beta-carbomethoxy-3 beta-(4-iodophenyl)tropane ([123I]beta-CIT).
Iodine-123-beta-CIT binding in the striatum was examined in 28 healthy human subjects (14 men, 14 women) who ranged in age from 18 to 83 yr. Following injection with [123I]beta-CIT (mean +/- s.d. = 9.9 +/- 1.2 mCi), subjects were scanned with the brain-dedicated CERASPECT camera. A reconstructed transaxial slice 13.3-mm thick at the level of maximal striatal activity was used to determine tracer uptake in striatal and occipital regions of interest. The stability of regional uptake on Day 2 (approximately 18-24 hr postinjection) permitted estimation of the specific-to-nondisplaceable equilibrium partition coefficient: V3", calculated as (striatal--occipital)/occipital uptake at equilibrium.
Values of V3" ranged from 3.6 to 11.4 for this sample (6.7 +/- 1.9). V3" showed a significant inverse correlation with age (r = -0.73, n = 28, p < 0.0001). Linear regression analysis revealed that V3" declined by 51% over the age range studied or approximately 8% per decade.
These findings confirm postmortem reports of dopamine transporter loss with aging. In vivo methodologies may permit the age-related degeneration of dopamine nerve terminals to be studied in relation to the cognitive and motor deficits that occur in normal aging.
使用配体[123I]2β-甲氧基羰基-3β-(4-碘苯基)托烷([123I]β-CIT)，通过单光子发射计算机断层扫描(SPECT)研究年龄对人类纹状体多巴胺(DA)转运体的影响。
对28名年龄在18至83岁之间的健康人类受试者(14名男性，14名女性)的纹状体中碘-123-β-CIT结合情况进行检查。注射[123I]β-CIT(平均±标准差=9.9±1.2毫居里)后，受试者使用脑专用CERASPECT相机进行扫描。在纹状体最大活性水平处重建的13.3毫米厚的横断面切片用于确定纹状体和枕叶感兴趣区域的示踪剂摄取。第2天(注射后约18 - 24小时)区域摄取的稳定性允许估计特异性与非置换性平衡分配系数：V3"，计算为平衡时(纹状体-枕叶)/枕叶摄取量。
该样本的V3"值范围为3.6至11.4(6.7±1.9)。V3"与年龄呈显著负相关(r = -0.73，n = 28，p < 0.0001)。线性回归分析显示，在所研究的年龄范围内，V3"下降了51%，即每十年约下降8%。
这些发现证实了关于多巴胺转运体随衰老而丧失的尸检报告。体内方法学可能有助于研究与正常衰老过程中出现的认知和运动缺陷相关的多巴胺神经末梢的年龄相关性退化。
